A trade-in involves customers exchanging a used product for credit toward a new item. This practice is common across industries, such as electronics or automotive. Customers trade in older items, like gadgets or vehicles, to offset the cost of a new purchase. Retailers assess the traded-in item's value based on factors like condition, applying it as a discount or credit toward the customer's new buy. This strategy fosters customer loyalty and stimulates sales by providing an incentive for upgrading or purchasing from the same retailer.